Pressure Effect of Curie Point of CoS₂ and Ferromagnetic Properties of Co(S_xSe_1−x)₂

Abstract

The change of the Curie point of CoS₂ under hydrostatic pressure up to 5.3 kbar was investigated, and the value of ΔT_c⁄ΔP was obtained to be −0.86 deg·kbar⁻¹. The linear compressibility of FeS₂, having approximately the same crystal structure with CoS₂, was measured, and the value of (1⁄l) (Δl⁄Δp) was given as 2.31×10⁻⁷ bar⁻¹ at 296°K. The relation between the change of the Curie point and the interatomic distance was obtained from the both results. This result was applied to an explanation of the ferromagnetic property of Co(S_xSe_1−x)₂, and the exchange interaction of this system was discussed. An iso-volume magnetic phase diagram of this system was illustrated.